The present invention relates to an inkjet printer for printing a substrate. The inkjet printer has a print zone and an inkjet printhead for printing the substrate in the print zone. In particular, the present invention relates to an inkjet printer for printing a substrate which is unwound from a roll.
The transport of a substrate unwound from a roll is more complex than the transport of sheets of a substrate. One reason for this is that the substrate has fewer degrees of freedom during the positioning thereof in the print zone. The trailing edge of the substrate is connected to the substrate that is still wound on the roll. There are therefore fewer possibilities of correcting faults occurring during the transport of the substrate or, for example, originating from inaccurate positioning of the roll in the printer supply unit. Another disadvantage of unwinding a substrate from a roll is the fact that the end of the roll cannot be predicted with high accuracy. It is therefore possible that at the beginning of printing of an image there appears to be sufficient substrate available to completely image the image on the substrate, but, in fact, during the printing it may be found that the amount of substrate still present on the roll is in fact insufficient to completely image the image on the substrate. It is known to stop printing as soon as it is found that a roll is completely unwound. However, since the distance between the roll and the print zone is often relatively considerable, a relatively large part of the substrate is not used in this case.